This invention relates generally to a fluid capsule pipeline system for transporting capsules over long distances, and more particularly to a capsule train separator for spacing consecutive capsules of solid material travelling in a pipeline at intermediate locations along the pipeline.
Fluid capsule pipelines represent an emerging technology by which freight is transported in the form of a capsule (such as a cylindrical shaped container or compacted, solid mass) carried by a fluid, usually water, moving through a pipeline. Such a mode of transportation has several potential advantages over conventional truck and rail modes, some of which are that it is less energy-intensive, less harmful to the environment, less labor-intensive and more economical in many circumstances. Fluid capsule pipeline system concepts are novel as compared to existing commercial gas or other fluid pipeline systems. The transport of solid objects presents mechanical design and control automation issues which are distinct from those associated with fluid transport (or from the transport of particulate solids which can be suspended in a fluid).
A fluid capsule pipeline system of the type to which the present invention presently relates is disclosed in U.S. Pat. No. 4,946,317. The pipeline system includes a manufacturing system where the capsules are formed or filled, an injection system to inject capsules into a pipeline, and an ejection system at the end of the pipeline for removing the capsules from the pipeline. Pressurized fluid such as water or gas is used to move the injected capsules through the pipeline.
After long stretches of transport, inevitable head losses in the system cause the velocity of the capsules to decrease. Should the velocity fall too far, the capsules would no longer be carried fully by the fluid and would engage the walls of the pipe forming the pipeline. Accordingly, booster stations are preferably provided to increase the head of the fluid thereby to maintain an adequate velocity for the capsules. However, in order to boost the fluid pressure, the solid capsules must be separated from at least a substantial portion of the fluid.
It is envisioned that capsules could be injected into the pipeline in trains (i.e., collections of capsules having a relatively close spacing) separated by a distance to permit the trains to be handled independently at the booster stations. However, it has been found that several trains may combine, with capsules touching each other or with random inter-capsule spacing and typically a continuous stream of capsules may approach the booster station. The small and greatly randomized spacing of the capsules makes it difficult for separation of the capsules from the fluid to occur at the booster stations.
Among the several objects and features of the present invention may be noted the provision of apparatus for separating capsules travelling in a pipeline which will reliably provide spacing between consecutive capsules; the provision of such apparatus which is mechanically simple and capable of separating the capsules without the use of valves or other mechanical components; the provision of such apparatus which inhibits the jamming of the capsules in the pipeline; the provision of such apparatus which provides sufficient spacing between consecutive trains of capsules to permit a diverter valve of a booster station to switch positions; the provision of such apparatus which minimizes head loss and transients associated with separating the trains of capsules; the provision of such apparatus which reduces the impact forces experienced by the capsules and pipeline; the provision of such apparatus which more efficiently controls operation of the booster station; the provision of such a capsule pipeline which includes safety features for immediately shutting down the pipeline in emergency situations.
Still further among the several objects and features of the present invention may be noted the provision of a method for boosting the pressure in a pipeline which can be carried out rapidly without substantial interruption in the travel of capsules through the pipeline; the provision of such a method which permits simple timed control; and the provision of such a method which operates the booster station efficiently while reducing the risk of emergency shutdown of the pipeline.
In general, apparatus of the present invention for spacing consecutive capsules of solid material travelling in a pipeline, the capsules being carried by a fluid flowing through the pipeline, comprises a separation system interposed between upstream and downstream portions of the pipeline for receiving capsules from the upstream portion and passing separated capsules to the downstream portion. The separation system is constructed for increasing the spacing between consecutive capsules in the downstream portion of the pipeline after passing through the separator.
Additionally, a method of the present invention for boosting fluid pressure in a pipeline system in which capsules of solid material are injected into a pipeline containing a flowing fluid to carry the capsules over long distances comprises positioning a valve to divert a first number of capsules defining a first train into a first lock of a boosting station. Fluid ahead of the capsules in the first train is then removed from the first lock. The valve is positioned to divert a second number of capsules defining a second train to a second lock at the boosting station and fluid ahead of the capsules in the second train is then removed from the second lock. The fluid removed from the second lock is pressurized and injected from the second lock into the first lock to increase the pressure of the fluid to carry the first train of capsules in the first lock into the pipeline at increased velocity. Capsules travelling through the fluid flow are separated to provide a spacing between the first and second trains prior to reaching the boosting station to permit the position of the valve to be switched between diverting capsules into the first lock and diverting capsules into the second lock.
Other objects and features will become in part apparent and in part pointed out hereinafter.